What (and all) I have heard, in the way of specs, for some of them, is the number of men they were (recommended) to carry - and I can't remember those numbers now. Judging from (especially USN) photos and models, though, there were at least three distinct sizes of them. Perhaps the most classic example: the stacked rafts on the Revell Yorktown-class mold. Carly floats on Airfix (600-scale) kits tend to be far, far smaller - but you never know about the scale-accuracy of such tiny details.
As a last resort, what could be done is to measure the raft parts on many models (of known scales), back-calculate their dimensions, and see what size(s) the majority "cluster" around - no doubt some round number(s), like 15-foot, 12-foot, etc.. I'll try to remember to think of it, next time I've drunk too much coffee!
Mike, did you send the writeup on your Barney pics? (I didn't receive any.) Send (or re-send) it and I'll post your pics - already have everything to get Craig's Gato posted, shortly.
I love you guys - among many, many others of The American People - and think about that on a day like today.
Semper Fi, Amigo!